Inflatable watercraft are commonly used for various types of water sports activities, such as fishing, hunting, touring/sightseeing, and wildlife photography, to give just a few examples.
Simple rubber rafts have been used for such purposes for many years, but their weight and poor handling qualities render them unsuitable for some uses, such as where the device must be packed a considerable distance to a fishing area, and/or must be highly-maneuverable in order to work in and about "holes" while fishing rivers or streams. For these reasons, there has been a trend in recent years towards single-person float tubes, in which the operator wears a set of waders or a wetsuit bottom and is supported from an encircling floatation tube (usually somewhat resembling a traditional "innertube") by a harness. While these devices are satisfactory for some purposes, notably fly fishing in comparatively small lakes, they lack sufficient stability and protection to permit safe operation on a river of any size, and furthermore they are simply not comfortable enough to use over an extended period of time when traversing a stretch of river or comparatively large body of water.
Some prior efforts have been made to achieve a satisfactory compromise between the conflicting requirements of compactness and stability/safety for use in rivers or for longer trips, but none of these has proven entirely satisfactory in practice. For example, U.S. Pat. Nos. 5,297,978 and 5,474,481 (both to Ramsey) show a craft which resembles an enlarged, oblong float tube, with a board or other rigid plank extending across the middle of the tube to provide a seat for the operator, whose feet protrude through a opening in the floor. While superior to traditional float tubes for some purposes, the usefulness of this device is limited by its reliance on the rigid platform (which serves a structural purpose as well as forming the seat), since this component makes the assembly difficult to fold compactly when deflated and also adds to its weight. Moreover, the craft positions the operator comparatively high out of the water, creating a high center of gravity and compromising the stability of the device, which can be a serious problem on rivers and streams. Also, the high seating position causes the operator's lower legs and feet to hang downwardly with the knees bent, which makes for very inefficient and tiring paddling with the feet, as opposed to an orientation where the legs can be kept more or less straight. Still further, the rigid board presents a wear/irritation problem where this rubs against the fabric of the inflatable tubes and the backs of the operator's legs.
Accordingly, there exists a need for an inflatable watercraft which is sufficiently light and compact when deflated that it can be conveniently packed over significant distances by a single person, yet which when inflated provides a high degree of stability and safety protection for operation on a river or other large or fast-moving body of water. Furthermore, there exists a need for such a craft in which the operator is positioned for both optimal comfort and efficient propulsion of the craft. Still further, there exits a need for such a craft which possesses a high degree of reserve buoyancy, and which can be constructed in an economical manner.